Slot Drill as a boring bar

[awemawson]

I wanted to bore rather than drill some 9.5 mm holes in aluminium alloy to keep them concentric prior to reaming to final size. However none of my boring bars were small enough.

Rather than grind a tool specifically I remembered a tip I picked up somewhere to use a single flute of a slot drill or end mill. Mounted the tool with the lip in question on centre height, but with the tool axis slightly pointing forward to create relief behind the rest of the sides and away we went. Worked very well so I post it here in case it helps someone else

Andrew

[Stilldrillin]

Thanks Andrew! I'm going to mount a slot drill in a spare holder. 

It's one of those wrinkles which you, know about. Until the moment arrives....... 

David D

[johnnyboy]

Interesting! I will certainly give that a try now I know someone else has tested it out!

cheers,
johnny

[chipenter]

TCT tiped router bits work very well to , I have saved about twenty from doing kitchen worktops I have thrown hundreds away over the years .

[Meldonmech]

Hi Andrew

                 A very good idea, I could have used one yesterday, must give it a whirl.

                                                                 Cheers  David

                                                       

[BaronJ]

Hi Guys,


I've used this trick several times !  With great success.  Particularly using an otherwise scrap cutter and hand regrinding it.  Putting a flat on the shaft helps too.


 

[dawesy]

no i like that idea.
always good to see alternate uses for tooling 

[Fergus OMore]

I've a home made 2" GHT boring head but mislaid the cutters. It was quite simple to substitute a slot drill using one lip.

Some time back, I recall that some one writing in Model Engineer used a broken twist drill as a lathe tool. One of my old associates once demonstrated how he used motor cycle spokes as miniature boring tools. He went on to show how he ground up Allen keys for the same purpose.

In his various books, GHT describes how broken centre drills are used to make boring tool bits, internal threading tools and parting tools.

I've been known to use cracked ball race cages- which are nice steel.

Nothing new, is there?

Norman

[BaronJ]

Hi Guys,
I've a number of broken carbide drill shanks.  1/8" diameter about an inch long.  They make great tool bits for boring bars.  They also make great dowel pins.